High-speed counterstroke hammer

ABSTRACT

A hammer is disclosed having crossbars with actuating tools secured thereto, which effect a counterstroke under the action of two coaxial power cylinders mounted on relevant cross-beams of the hammer frame. The top crossbar is returned into the initial position under the action of hydraulic cylinders, mounted on the bottom crossbeam and having a connection through hydraulic means with the bottom power cylinder, while the bottom crossbar is under the action of air-hydraulic cylinders mounted on the top cross-beam and having a connection through hydraulic means with the top power cylinder made as an air-hydraulic receiver.

United States Patent [191 Kononenko et al. [4 1 July 9, 1974 [54] HIGH-SPEED COUNTERSTROKE HAMMER 3,596,492 8/1371 Sauerbrey 72/453 3,707,86 1/1 73 Brauer 72 407 [76] Inventors: f g ig 3,735,631 5/1973 Schmoll 72/407 ulsac aova, v. 0r

g g gfsg tg Primary Examiner-Charles W. Lanham Anatoly Stepanovich Chernyavsky, jif ixamtmernggene g; St ulitsa Chkalova, 15, all of Kharkov, omey gen or lrm 0 man em USSR. 2 F d 0c 2 1 72 [57] ABSTRACT 2] He 9 A hammer is disclosed havingcrossbars with actuating [21] Appl. No.: 300,238 7 tools secured thereto, which effect a counterstroke under the action of two coaxial power cylinders mounted on relevant cross-beams of the hammer [52] US. Cl 72/407, 72/453, 110004226649, frame- The p crossbar is returned into the initial p Int Cl B2 9/12 sition under the action of hydraulic cylinders, mounted on e bottom crossbeam and having a [58] Fleld of Search 72/407, 453, 100/264, 269 nection through hydraulic means with the bottom [56] References Cited power cylinder, while the bottom. crossbar is under the action of air-hydraulic cylinders mounted on the top UNITED STATES PATENTS cross-beam and having a connection through hydrau- 2,863,343 12/1958 Steinfort 72/407 means the top power ylinder made as an air- 3,209,578 10/1965 Muller 72/453 hydraulic receiven 3,353,396 11/1967 Brauer 72/453 3,429,174 2/1969 Fracke 72/453 2 Claims, 3 Drawing Figures M, 25 Ii 1 2 w I 2 17 f4 i 1 HIGH-SPEED COUNTERSTROKE HAMMER The present invention relates to pressure shaping of materials, and in particular, to high-speed counterstroke hammers utilizing the energy of steam or highpressure gas for effecting the counter acceleration of impact parts with working tools fitted thereon for processing the blank.

Known in the art are high-speed counterstroke hammers, wherein the working tools are installed in opposition to each other on two horizontally mounted crossbars, adapted to be displaced in the vertical direction along the guides of the fixed frame of the hammer.

The counter working stroke of these crossarms is effected under the action of two coaxial power cylinders mounted on the top and bottom cross-beams of the frame. The cavity of the bottom power cylinder communicates with the cavities of two hydraulic cylinders mounted on the bottom cross-beam of the frame in symmetry with respect to its axis and connected through their rods to the top crossbar. Such a hydraulic communication between the crossbars ensures synchronism in displacement of the latter in the course of the working stroke.

The top crossbar is returned into the initial position by supplying the power agent (compressed air or fluid) stroke under the action of two coaxial power cylinders, mounted on the top and bottom crossbeams of the frame, along its axis, the cavity of the bottom power cylinder communicating with the cavities of at least two hydraulic cylinders, installed on the frame bottom cross-beam in symmetry with respect to its axis and v connected through their rods with the top crossbar.

into the bottom cavity of the top power cylinder,

whereas the bottom crossbar is lowered under the action of its own weight.

One of the drawbacks of known hammers is that the the working strokes of the crossbars have a length which considerably exceeds that of the plungers of the power cylinders, thus limiting the possibility of developing high specific pressures due to inertia overloads arising in the rods during the working stroke of the crossbars. The increase in the rigidity of the rods at the expense of enlarging the cross-sectional area (in order to preclude possible'loss of stability) leads to an increase in resilient strain of these rods and to a decrease in the efficiency of the hammer impact as a whole.

Besides, the gravity return of the bottom crossbar into the initial position limits the range of application of such hammers due to the fact that the weight of the crossbar is not always sufficient for ejecting the processed blank from the working tool secured to the crossbar.

It is an object of the present invention to provide a highspeed counterstroke hammer wherein the rods of hydraulic cylinders responsible for synchronizing the working strokes of the crossbars by hydraulic means have a minimum length which does not exceed that of the plungers of the power cylinders, thus making possible to provide a more powerful and reliable highspeed hammer possessing higher efficiency.

Another object of the present invention is also to provide a postive return into the initial position of the bottom crossbar.

Still another object of the invention is to provide ejection of the blank from the working tool secured to the bottom crossbar.

These and other objects are attained in a high-speed counterstroke hammer wherein the working tools for processing the blank are arranged in opposition to each other on relevant crossbars, mounted so as to be displaced vertically along the guides of a frame rigidly on a foundation,- in order to perform counter working rods of the hydraulic cylinders used for synchronizing According to the invention, the top power cylinder is made as an air-hydraulic receiver, the hydraulic cavity thereof communicating with the cavities of at least two air-hydraulic cylinders, mounted on the top cross-beam of the frame in symmetry with its axis and connected through their rods with the bottom crossbar in order to ensure returning of the latter into initial position with simultaneous ejecting of the processed blank from the working tool secured to the bottom crossbar.

Such a construction allows for reducing considerably the length of rods of hydraulic cylinders serving for synchronizing the stroke of hydraulic means, and hence, for diminishing inertia loads applied to them, this feature resulting finally in an increase of specific pressures and total efficiency of the hammer, according to the invention, having the same weight and overall dimensions as known hammers. It is advantageous that the treated blank is ejected from eachworking tool, secured to the bottom crossbar with the help of an ejector, fastened with one end to the bottom of the power cylinder, along its axis, and passing unobstructedly through open coaxial ducts made in the plunger of this cylinder, in the bottom crossbar and in the actuating tool fastened thereto.

Availability of ejectors broadens the processing capabilities of the hammer owing to a wide range of parts to be processed, their shape, weight, etc, also, ensures reliable performance of the hammer.

The invention will now be explained in greater detail with reference to an embodiment thereof taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic representation of the general view of the high-speed counterstroke hammer, according to the invention, with detail of longitudinal section;

FIG. 2 is a cross-section taken along the line II-II of FIG. 1; 7

FIG. 3 is a cross-section taken along the line III-III of FIG. 1.

A high-speed counterstroke hammer, according to the invention, comprises a vertical frame 1 (FIG. 1),

rigidly installed on a foundation and formed by a top and bottom horizontal cross-beams, 2 and 3 respectively, interlinked by means of two vertical uprights 4, along the guides of which can be displaced in the vertical direction two horizontal crossbars: top and bottom, 5 and 6 respectively.

On the top cross-beam 2 of the frame 1 along its longitudinal axis is mounted on a top power cylinder 7, made as an air-hydraulic receiver with a plunger 8. A cavity 9 of the receiver 7 is filled with high-pressure gas, such as nitrogen under a pressure of from I00 to I50 atm, while the bottom portion of the cavity 9 is filled with working fluid 10.

In the process of operation the plunger 8 of the receiver 7, being accelerated under the action of gas, actuates the external surface of the top crossbar 5., displacing the latter downwards in the direction of the bottom crossbar 6.

On the upper cross-beam 2 of the frame 1 in symmetry with its axis, according to the invention, are mounted also two air-hydraulic cylinders 11 (FIG. 1 and 2), the cavities thereof communicating with the hydraulic portion of the cavity 9 of the receiver 7. Free ends of hollow rods 12 of these cylinders 11 are fastened with nuts 13 in relevant threaded holes made on the internal (die) plane of the bottom crossbar 6.

The air-hydraulic cylinders 11 are intended for returning the bottom crossbar 6 into the initial (bottom) position.

In order to ensure efficient operation of the hydraulic drive, the total cross-sectional area of the rods 12 of the cylinders 11 is selected to be equal to that of the rod 8 of the receiver 7.

On the bottom cross-beam 3 of the frame 1 is mounted coaxially with the receiver 7, a bottom power cylinder 14, the plunger 15 thereof actuating, in the process of the hammer operation, the external plane of the bottom crossbar 6, displacing the latter upwards.

Besides, on the bottom cross-beam 3 of the frame 1 insymmetry with its longitudinal axis are fastened in pairs four hydraulic cylinders 16 (FIG. 1 and 3), the cavities thereof being connected by hydraulic means with the cavity of the bottom .power hydraulic cylinder 14. The hollow rods 17 of the hydraulic cylinders 16 are fastened with nuts 18 in the threaded holes made in the internal (die) plane of the top crossbar 5.

In the air-hydraulic cylinders 11 incorporated in the hammer, according to the invention, the rods 17 of the hydraulic cylinders 16, as well as the rods 12 of the top cylinders 11 have a length which is less than that of the plungers 8 and 15 of the power cylinders 7 and 14, this feature helping to reduce the inertia loads applied to the rods 17 and 12 and allowing for the specific pressure of the hammer as a whole to be increased.

On the internal (die) surfaces of both crossbars and 6, along the axis of the hydraulic cylinders 7 and 14, are fastened working tools 19 and 20, opposing each other, dies in our example, between which blank 21 is being processed, placed on the bottom die 20.

In the bottom 22 of the receiver 7 and in the bottom 23 of the bottom power hydraulic cylinder 14, along their axes, according to the invention, are secured push-rods 24 and 25, respectively, freely passing through open coaxial ducts made in respective plungers 8 and 15, crossbars 5 and 6 and dies 19 and 20. With their free ends the push-rods 24 and 25 actuate the heads of ejectors 26 and 27 mounted in respective dies 19 and 20.

The high-speed counterstroke hammer operates as follows.

In FIG. 1 the hammer is shown in the initial position, i.e., the crossbars 5 and 6 respectively occupy the extreme top and extreme bottom positions.

To effect an impact against the blank 21 placed on 4 the bottom die 20, to the bottom power cylinder 14 via the pipe union 28 is supplied the working fluid under a pressure developed by the hydraulic drive (not shown), under the action of which the plunger 15 starts moving upwards (in the drawing), leaving the sealing seat of the power cylinder 14.

Following this, the pressure of gas in'the receiver 7 forces its plunger 8 downwards rapidly, displacing in the same direction the top crossbar 5, which in depressing the rods 17 of the hydraulic cylinders 16, makes the fluid squeeze out of their .cavities into the cavity of the bottom power cylinder 14, accelerating in this way its plunger 15 together with the bottom crossbar 6 at the same speed at which the top crossbar 5 travels downwards.

In synchronism with the downward travel of the top crossarm 5 the rods 12 of the cylinders 11 will force the working fluid out of their cavities into the cavity of the receiver 7, compressing the gas.

Thus owing to hydraulic communication between the cylinders 14 and 16 the synchronism in the working strokes of both the top and bottom crossarms 5 and 6 is achieved, thereby increasing the reliable operation of the hammer.

At the instant the crossarms 5 and 6 and corresponding dies 19 and 20 approach each other, the blank 21 is being deformed. Then, using the pipe union 28, the cavity of the hydraulic cylinder 14 is connected with the drain and the bottom crossarm 6 lowers to occupy its initial position under the action of the rods 12 of the air-hydraulic cylinders 11, which are forced by the fluid and gas contained in the receiver 7.

Hereat the ejector 27 will thrust with its head against the end of the push-rod 25 and with further'displacement of the crossarm 6 upwards pushes out the processed blank 21 from the seat of the die 20.

Once the plunger 15 of the bottom power cylinder 14 has reached its extreme bottom position, the pipe union 29 communicates the cavity of the cylinder 14 with the hydraulic drive. Hereat the fluid from the cavity of the power cylinder 14 flows into the cavity of the hydraulic cylinders 16, displacing upwards their rods 17, which return the top crossarm 5 and the plunger 8 of the receiver 7 into initial (top)position, compressing the gas in the cavity 9 of the receiver 7.

At this instant the ejector 26 of the top die 19 thrusts against the end of the top push-rod 24, and in case the blank 21 is left in the top die 19, pushes it out of the die 19.

Further the operating cycle of the hammer is repeated.

The high-speed hammer executed according to the present invention can be used for processing highstrength materials.

What we claim is:

l. A high-speed counterstroke hammer, comprising: a frame rigidly fixed on a foundation and formed by a top and bottom cross-beams interlinked by means of uprights with guides; two crossbars mounted in the guides of said frame and adapted to be displaced vertically; working tools for processing the blank, secured in said crossbars in opposition to each other along the axis of said frame, two coaxial power cylinders mounted respectively on the top and bottom crossbeams of said frame along its axis and intended for displacing relevant said crossbars towards each other during their working stroke; said power cylinder mounted on the top cross-beam being an air-hydraulic plungertype receiver; at least two air-hydraulic cylinders, also mounted on the top crossbeam of said frame in symmetry with respect to its axis and linked through their rods with said bottom crossbar in order to bring it into the initial position after the working stroke has been performed with simultaneous ejection of the processed blank from the working tool fastened in said bottom crossbar; said air-hydraulic cylinders having cavities communicating with a hydraulic cavity of said receiver; said power cylinder mounted on the bottom cross- 2. A hammer as claimed in claim 1, wherein the processed blank is ejected from the working tool, secured to the bottom crossbar, with the help of a push-rod fastened with one end to the bottom of the bottom power cylinder along its axis and freely passing through open coaxial ducts made in a plunger in the bottom power cylinder, bottom crossbar and working tool. 

1. A high-speed counterstroke hammer, comprising: a frame rigidly fixed on a foundation and formed by a top and bottom cross-beams interlinked by means of uprights with guides; two crossbars mounted in the guides of said frame and adapted to be displaced vertically; working tools for processing the blank, secured in said crossbars in opposition to each other along the axis of said frame, two coaxial power cylinders mounted respectively on the top and bottom cross-beams of said frame along its axis and intended for displacing relevant said crossbars towards each other during their working stroke; said power cylinder mounted on the top cross-beam being an airhydraulic plunger-type receiver; at least two air-hydraulic cylinders, also mounted on the top crossbeam of said frame in symmetry with respect to its axis and linked through their rods with said bottom crossbar in order to bring it into the initial position after the working stroke has been performed with simultaneous ejection of the processed blank from the working tool fastened in said bottom crossbar; said air-hydraulic cylinders having cavities communicating with a hydraulic cavity of said receiver; said power cylinder mounted on the bottom cross-beam of said frame representing a hydraulic cylinder; at least two hydraulic cylinders mounted on the bottom cross-beam of said frame in symmetry with its axis and linked through their rods with said top crossbar; said hydraulic cylinders having cavities communicating with a cavity of said hydraulic power cylinder in order to bring in synchronism the working strokes of said crossbars.
 2. A hammer as claimed in claim 1, wherein the processed blank is ejected from the working tool, secured to the bottom crossbar, with the help of a push-rod fastened with one end to the bottom of the bottom power cylinder along its axis and freely passing through open coaxial ducts made in a plunger in the bottom power cylinder, bottom crossbar and working tool. 